A fortress going in adventure time seems to fast. Years would progress too quickly, and not enough work could get done in that time frame for it to seem like years should be passing.
On the flipside, I don't think having a fortress running in real time would be all that practical either. There must be abstractions made for the sake of gameplay. A perfectly accurate simulation would also make for a terrible game. If you want a perfectly accurate simulation of life, just go outside.
Consider that a dwarf would need to eat and drink multiple times per day. Growing a crop will take months to finish. I'm not talking in-game months, which is fine, but real life months. That would be silly if I start a fortress right now, I'm playing 24/7, and I don't get in my first plump helmet harvest until March. And this isn't even getting into other dwarven needs, such as sanitation. I agree with Toady on this one, in that adding in sanitation to the game would be horrific. While engineering sewers would be fun, weaponized sewage and other filth would be all kinds of ick.
Also consider dwarven children. Its already very generous with a 12 year old being considered an adult in a fortress. I'm not waiting through 4 presidential administrations before Urist McBaby is old enough to be given an axe and go chopping goblins.
I think the current balance of time compression in fortress mode gets it about right. Things are abstracted, yes, but time also progresses quickly enough that a player can build things and have generations of dwarves living in a long term fortress, yet time is also slow enough that there is a sense of the passage of time and seasons.
Sometimes things can get silly, such as it taking half a year to clean up from a single goblin siege, depending on how many giblets are created, or hauling nightmares created by reorganizing your stockpiles, causing everything needing to be resorted, but all in all, I think Toady got the balance of realism vs playability right when it comes to time.